Z-axis alignment of an optoelectronic component using a composite adhesive

ABSTRACT

An optoelectronic package that employs a spacer tool system to properly align an optical component within the device is disclosed. In one embodiment, the package includes a mounting surface, and an optical component positioned on the mounting surface at a predetermined distance from a reference point. The optical component is positioned at the predetermined distance by a spacer tool, wherein the spacer tool is interposed between the optical component and a spacer tool mount during optical component positioning. The spacer tool is of a length that corresponds with the predetermined distance between the optical component and the reference point.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/590,280, filed Jul. 22, 2004, which is incorporatedherein by reference in its entirety.

BACKGROUND

1. The Field of the Invention

The present invention is generally directed to optoelectronic devices.More particularly, the present invention is directed to the alignment ofa component within an optoelectronic device so as to provide forefficient assembly of the device.

2. The Related Technology

Fiber-optics and optoelectronics are important aspects of modern opticalnetworks because they allow for efficient, accurate and rapidtransmission of optical data between various components in the networksystem. Optical transceiver modules (“transceivers”) are an example ofmodular components used in optical networks. Such modular component aredesirable in optical networks and other fiber optic systems to reducethe cost of manufacturing the system, which cost increases the morecustomized the system becomes.

Transceivers usually include an input receiver optical subassembly(“ROSA”) and an output transmitter optical subassembly (“TOSA”). TheROSA includes a photodiode for detecting optical signals and sensingcircuitry for converting the optical signals to electrical signalscompatible with other network components. The TOSA includes a laser fortransmitting optical signals and may include control circuitry formodulating the laser according to an input digital data signal as wellas a photodetector to monitor laser power. The TOSA has an optical lensfor focusing the optical signals from the laser of the TOSA into anoptical fiber. Similarly, the ROSA often includes a lens to focusincoming optical signals on the photodiode. Additionally, one end of thetransceiver includes pluggable receptacles, pig-tailed connections, orother suitable means for optically connecting the TOSA and the ROSA withother components within a fiber optic network, while another end oftenincludes a connector for connecting with electrical components of a hostsystem or device with which the transceiver communicates.

The photodiode in the ROSA and the laser in the TOSA are examples ofoptoelectronic semiconductor components. Generally, these optoelectronicsemiconductor components are sensitive devices that require mechanicaland environmental protection. As such, these optoelectronic componentsare usually manufactured in packages to provide such protection and tofacilitate their incorporation into higher level devices, such as TOSAsand ROSAs.

One such packaging assembly is known as a transistor-outline header ortransistor-outline package, referred to herein as a TO package. TOpackages are widely used in the field of optoelectronics, and may beemployed in a variety of applications. As such, TO packages are oftenstandardized to facilitate their incorporation into components such astransceivers. The TO packages protect the sensitive electrical devicescontained therein and electrically connect such devices to externalcomponents such as printed circuit boards (“PCB”).

With respect to their construction, the TO packages often include acylindrical metallic base, also known as a header, with a number ofconductive leads extending completely through, and generallyperpendicular to, the base. The size of the base is often sized to fitwithin a specific TO standard size and lead configuration, examples ofwhich include a TO-5 or TO-46. The leads are usually hermetically sealedin the base to provide mechanical and environmental protection for thecomponents contained in the TO package, and to electrically isolate theconductive leads from the metallic material of the base. Typically, oneof the conductive leads is a ground lead that may be electricallyconnected directly to the base.

Various types of electrical devices and optical components, such as thephotodiode or laser device, are mounted on an interior portion of thebase and connected to the leads to enable their operation. Generally acap, also known as a can, is used to enclose the interior portion of thebase where such electrical devices are mounted so as to form a hermeticchamber that helps prevent contamination or damage to the devices. Thespecific design of the TO package depends on the optoelectroniccomponent being mounted on the base and the modular component with whichthe TO package will be used. By way of example, in applications wherethe optoelectronic component mounted on the base is an opticalcomponent, i.e., a laser or photodiode, the cap is at least partiallytransparent so as to allow an optical signal generated or received bythe optical component to be transmitted to or from the TO package. Theseoptical TO can packages are also known as window cans.

In the case of mounting optical components within a window can or otherTO package within an optical subassembly, various challenges are oftenencountered. One challenge deals with accurately positioning the opticalcomponent, such as a laser or photodiode, with respect to anothercomponent, such as the lens, which may be included in, or proximate to,the package in the optical subassembly. Such positioning is critical toensure that the optical signals are properly collimated or otherwisefocused upon entry to or exit from the optical transceiver module orrelated device.

In light of the above, a need exists for a means by which a laser,photodiode, or other semiconductor and/or optoelectronic component canbe properly positioned in an optoelectronic or other package such thatoperation of the device in which the component is disposed is optimized.

BRIEF SUMMARY

The present invention has been developed in response to the above andother needs in the art. Briefly summarized, embodiments of the presentinvention are directed to

An optoelectronic package that employs a spacer tool system to properlyalign an optical component within the device is disclosed. In oneembodiment, the package includes a mounting surface, and an opticalcomponent positioned on the mounting surface at a predetermined distancefrom a reference point. The optical component is positioned at thepredetermined distance by a spacer tool, wherein the spacer tool isinterposed between the optical component and a spacer tool mount duringoptical component positioning. The spacer tool is of a length thatcorresponds with the predetermined distance between the opticalcomponent and the reference point.

In another embodiment, a method of positioning a first component withrespect to a second component in an optoelectronic package is disclosed.The method includes determining a desired position of the firstcomponent with respect to the second component, then determining anamount of spacing between the first component and a reference point thatis required to position the first component at the desired position. Aspacer tool that has a length equal to the required amount of spacing toposition the first component at the desired position is employed, thenthe first component is affixed at the desired position.

These and other features of the present invention will become more fullyapparent from the following description and appended claims, or may belearned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof that areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 is a perspective view of an exemplary optical transceiver module,in which one embodiment of the present invention can be practiced;

FIG. 2A is a perspective view of an optical subassembly including oneembodiment of the present invention;

FIG. 2B is a perspective view of another optical subassembly includingone embodiment of the present invention;

FIG. 3 is a partial cutaway view of an optical package, including alaser die that can be properly aligned in accordance with one embodimentof the present invention;

FIG. 4 shows the optical package of FIG. 3, having the laser diedesirably positioned in accordance with one embodiment;

FIG. 5 is a perspective view of a spacer tool that is employed inaligning the laser die of FIG. 3; and

FIG. 6 is a simplified block diagram of a system for positioning anoptoelectronic component, such as the laser die of FIG. 3, to a package,according to one embodiment.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made to figures wherein like structures will beprovided with like reference designations. It is understood that thedrawings are diagrammatic and schematic representations of exemplaryembodiments of the invention, and are not limiting of the presentinvention nor are they necessarily drawn to scale.

FIGS. 1-6 depict various features of embodiments of the presentinvention, which is generally directed to the alignment of an optical oroptoelectronic component, such as a laser die or photodiode, within anoptical device in such a way as to simplify both the assembly of thedevice as well as the manufacture of its constituent parts. This, inturn, can reduce costs associated with the manufacture of opticaldevices that benefit from the teachings contained herein.

Reference is first made to FIG. 1, which depicts a perspective view ofan optical transceiver module (“transceiver”), generally designated at100, for use in transmitting and receiving optical signals in connectionwith an external host that is operatively connected in one embodiment toa communications network (not shown). As depicted, the transceiver shownin FIG. 1 includes various components, including an optical receiverimplemented as a receiver optical subassembly (“ROSA”) 10, an opticaltransmitter implemented as a transmitter optical subassembly (“TOSA”)20, electrical interfaces 30, various electronic components 40, and aprinted circuit board 50. In detail, two electrical interfaces 30 areincluded in the transceiver 100, one each used to electrically connectthe ROSA 10 and the TOSA 20 to a plurality of conductive pads located onthe PCB 50. The electronic components 40 are also operably attached tothe PCB 50. An edge connector 60 is located on an end of the PCB 50 toenable the transceiver 100 to electrically interface with a host (notshown here). As such, the PCB 50 facilitates electrical communicationbetween the ROSA 10/TOSA 20, and the host. In addition, theabove-mentioned components of the transceiver 100 are partially housedwithin a housing portion 70. Though not shown, a shell can cooperatewith the housing portion 70 to define a covering for the components ofthe transceiver 100.

Reference is now made to FIGS. 2A and 2B. As will be described, the TOSA20 and ROSA 10 are examples of components within an optical device, suchas the transceiver 100, that can benefit from the alignment principlesto be discussed herein in connection with embodiments of the invention.In particular, the TOSA 20 generally includes an optoelectronic packagethat houses a laser die, to be described below, for producing an opticalsignal in connection with transceiver operation. Similarly, the ROSA 10includes an optoelectronic package that houses a photodiode (not shown)for receiving an optical signal in connection with transceiveroperation. As a prerequisite for their proper operation in transmittingand receiving optical signals, the laser die and the photodiode must beproperly aligned with respect to other components within theirrespective packages. The principles of the present invention provide forsuch alignment in the direction of light propagation or reception,referred to herein as the z-axis direction (see coordinate axes in FIG.3).

Notwithstanding the above discussion, it should be remembered that thepresent invention can be practiced in connection with a variety of otheroptoelectronic components and optical devices, or with opticalsubassemblies that vary in structure or design from that depictedherein. Thus, the discussion presented herein should not be construed tolimit the present invention in any way.

As mentioned above, the ROSA 10 includes as part of its structure anoptoelectronic TO header package (“package”) 150 containing one or moreoptical components. In the present embodiment, the package 150 of theROSA 10 includes a photodiode (not shown) configured to receive andsense optical signals received by the ROSA for conversion intoelectrical signals. This configuration is commensurate with use of theROSA within the transceiver 100.

Similarly, the TOSA 20 includes an optoelectronic TO header package(“package”) 200 containing a laser die (not shown here) that isconfigured to produce an optical signal containing digital data fortransmission onto an optical fiber. As such, the packages 150 and 200serve as examples of an optoelectronic device for use with embodimentsof the present invention. In addition, other devices can benefit fromthe principles contained herein. As such, the features of the ROSA 10and TOSA 20, together with their corresponding packages, are notnecessarily significant to this particular invention, but are providedfor purposes of enablement.

In detail, the package 150 of the ROSA 10 includes a base 152 throughwhich extends a plurality of conductive leads 153. Each lead 153 iselectrically isolated from the base 152 by glass seals. The leads 153serve to electrically interconnect components contained in the package150, such as the photodiode referred to above, with components,supplies, etc., that are located outside of the ROSA 10. In oneembodiment, the leads 153 are in electrical communication with the PCB50 via one of the connectors 30.

Similarly, the package 200 of the TOSA 20 includes a base 202 throughwhich extends a plurality of conductive leads 203, insulated bycorresponding glass seals. As with the package 150, the leads 203 of thepackage 200 serve to electrically interconnect components contained inthe package 150, such as the laser die or other light emitter referredto above, with components located outside of the TOSA 20, such as thePCB 50 via one of the connectors 30.

Reference is now made to FIG. 3 in describing various details regardingone embodiment of the present invention. In detail, FIG. 3 shows, insimplified block form, an optoelectronic package that forms a part of anoptical subassembly. In the illustrated embodiment, the package isconfigured as the laser die-containing housing, or package 200, whichforms part of the TOSA 20, as described above. The laser package 200includes a first package portion 204 and a second package portion 206that correspondingly mate with one another to form the package. Itshould be noted that, while it is shown to have a particularconfiguration, the package 200 is merely representative of the varietyof package shapes and configurations in which principles of the presentinvention can be practiced. For instance, the package could be formedfrom one, two, or more portions, and the portions could vary in size anddesign from that which is shown in FIG. 3. Additionally, as has alreadybeen described, principles of the present invention can be practiced inconnection with other components, such as the ROSA 10 shown in FIG. 2A,or other devices.

As shown in FIG. 3, in one embodiment the first package portion 204 andsecond package portion 206 are mated with one another at a matinginterface of both portions. The mating interface corresponds with apackage reference 208 that is defined at the interface of the first andsecond package portions 204 and 206. The package reference 208 is usedin the present embodiment to assist in aligning an optical component ofthe laser package 200 using the alignment procedures described below.Note that, though the package reference 208 of the embodiment shown inFIG. 3 is defined by the interface between the first package portion 204and the second package portion 206, other package references could bedefined in addition to or instead of the one shown here.

The package 200 further provides a location for the positioning andplacement of an optical component. Specifically, FIG. 3 shows a mountingsurface 210 defined on the base 202 of the second package portion 206.Alternatively, the mounting surface could be defined on a submount thatis attached or defined by the base or second package portion, or anothersuitable surface. The mounting surface 210 is suitably shaped to receivean optoelectronic component of the laser package 200. In the presentembodiment, the optoelectronic component is a laser die 212. FIG. 3shows the laser die 212 temporarily resting on the mounting surface 210before being permanently affixed thereto via an adhesive in a manner tobe described below. As such, the mounting surface 210 serves as apermanent base for the laser die 212. Note that the mounting surface 210can have a variety of shapes and configurations in accordance with theneeds of the package. For instance, a lead frame, flexible circuit, PCB,etc. can be positioned to interconnect with the laser die 212 via wirebonds or other suitable means once the die is permanently affixed.

The second package portion 206 includes a focusing element, such as alens 214. The lens 214 is positioned adjacent an outlet 216 that enablesan optical signal produced by the laser die 212 and focused by the lensto exit the laser package 200. As such, the laser die 212 and the lens214 are aligned with respect to one another and with respect to theoutlet 216. In another embodiment, the lens can be positioned as acomponent separate from the package 200.

In the configuration shown in FIG. 3, the laser die 212 is a verticalcavity surface emitting laser (“VCSEL”), and as such emits light from anemitting surface 212A that is substantially parallel to the mountingsurface 210. Thus, optical signals emitted by the emitting surface 212Aof the VCSEL laser die 212 in this embodiment propagate in the z-axisdirection as indicated by the coordinate axes in FIG. 3. Note that otherlasers and light emitting semiconductors, such as LED's andedge-emitting lasers, can also be used in connection with embodiments ofthe invention, as appreciated by one skilled in the art.

In the configuration of the laser package 200 shown in FIG. 3, severalpertinent dimensions can be defined in the z-axis direction in order toprovide data for the proper z-axis alignment of the laser die 212 inaccordance with embodiments of the present invention. A distance betweenan optical input side 214A of the lens 214 and the package reference 208is defined as a distance Z1. An optimum distance between the emittingsurface 212A of the laser die 212 and the input side 214A of the lens214 in the z-axis direction is designated Z2. And a dimension Z3 definesthe distance between the package reference 208 and the emitting surface212A of the laser die 212 at the after the laser die is desirablypositioned at the optimum distance Z2.

As shown in FIG. 3, the emitting surface 212A of the laser die 212 maybe at a level that is initially below the optimum distance from the lensinput side 214A, indicated at Z2, after initial assembly of the laserpackage 200 is complete. Embodiments of the present invention aredesigned to eliminate this discrepancy in order to provide optimum laserdie-to-lens spacing in the z-axis direction. Again, though the presentembodiment shows a laser die and a lens, other optoelectronic andoptical components can be desirably aligned using the principles of thepresent invention, including photodiodes associated with a receiveroptical subassembly.

Reference is now made to FIG. 4, which depicts use of a spacer tool,generally designated at 700, in properly aligning in a z-axis directionan optical device in a package, such as the laser die 212 in the laserpackage 200. As such, FIG. 4 is a successive view of the laser package200 of FIG. 3, following application of alignment procedures of thepresent invention in accordance with one embodiment thereof. As shown,the laser die 212 is affixed to the mounting surface 210 of the secondpackage portion 206 via an adhesive 310, which can further includesolder, adhesive strips, or other suitable affixing means. Placement ofthe laser die 212 on the mounting surface 210 via the adhesive 310 issuch that its emitting surface 212A is positioned a desired distance Z2from the input side 214A of the lens 214. Advantageously, the distanceZ2 between the laser die 212 and the lens 214 represents an optimumorientation in the z-axis direction of the laser die with respect to thelens.

As previously mentioned, alignment of the laser die 212 shown in FIG. 4is accomplished by detailed measurement of the various dimensions of thelaser package 200 and associated components indicated by dimensionsZ1-Z3, and by employing the spacer tool 700. In detail, after initialassembly of the laser package 200 and temporary placement of the laserdie 212 on the mounting surface 210 of the second package portion 206,the laser package is inspected using a suitable method or device ormethod to determine the values of the various dimensions Z1-Z3 that areshown in FIG. 3. This can be accomplished using an imaging camera orother optical or physical measurement apparatus. In one embodiment thedimension Z3 can be determined by subtracting the value of Z1 from thevalue of Z2. In another embodiment, however, Z3 can be opticallymeasured independently of other measurements. Similarly, dimension Z2can be determined independent of the other dimensions, or can bedetermined using dimensions or techniques beyond those discussed herein,as appreciated by those skilled in the art.

Determination of Z1 and Z2 enables in turn the determination of thedesirable alignment and positioning of the laser die with respect to thedirection of light propagation, i.e., the z-axis, within the package200. The desired position with respect to the package reference 208 isindicated in FIG. 3 as dimension Z3, and in one embodiment is determinedby the formula Z3=Z2−Z1. As such, dimension Z3 can be considered todefine the ideal z-axis position of the laser surface with respect toreference surface 208 to ensure that the laser surface will bepositioned at a distance Z2 from lens surface 214A. Any error in thestarting position of the laser surface can therefore be corrected by useof the spacer tool 700. It is further noted here that considerationshould be made in determining and using the various dimensions notedherein of any additional discrepancy that may be introduced by thethickness of typical adhesive that is used to bond the first and secondpackage portions 204 and 206 together at their mutual interface, in thiscase, the package reference 208. Note, however, that in the presentembodiment only the second package portion is directly employed duringthe alignment procedures to be described below.

As FIG. 4 illustrates, once the dimension Z3 is determined, a spacertool, such as spacer tool 700 shown in FIG. 5, is selected, having acorresponding length equal to the Z3 dimension, as shown. FIG. 5 showsone example of the spacer tool 700, which in the present embodiment isblock-shaped. The spacer tool 700 is attached to a mount 710 that caninterface with the package reference 208. As such, during packageassembly the laser die 212 is temporarily attached to the spacer tool700, which in turn is attached to the mount 710. Such temporaryattachment can be achieved via adhesive, a vacuum configuration, orother suitable means.

The mount 710 is then brought into contact with the package reference208 of the second package portion 206. This brings the laser die 212into proper z-axis alignment with respect to the package reference 208.A sufficient amount of adhesive 310, previously placed on the mountingsurface 210 of the second package portion 206, affixes the laser die 212in place. The mount 710 and spacer tool 700 can remain in place untilthe adhesive is sufficiently hardened or until the laser die issufficiently affixed in place. In one embodiment, an epoxy is employedas the adhesive 310 such that, once the laser die 212 is properlypositioned in the adhesive, the epoxy can be flash cured, therebysecuring the laser die in place.

The mount 710 together with the spacer tool 700 are then removed fromthe second package portion 206, and assembly can continue as needed tocomplete the package. So configured, the emitting surface 212A of thelaser die 212 is desirably aligned the distance Z3 from the packagereference 208 in the z-direction.

It is relatively common that during package manufacture the relativesizes and fit of the respective components of each package can vary frompackage to package, due to tolerances and other manufacturing variancesthat are inherent in the manufacturing and assembly process. Forinstance, one package; such as the package 200 shown in FIG. 2, canpossess dimensions Z1 and Z2 that vary from those dimensions of asubsequent package manufactured using the same process. Embodiments ofthe present invention are designed to compensate for this and othersimilar variance. In detail, multiple spacer tools can be configured tocorrespond to packages having varying Z3 distances. Thus, once theneeded dimension Z3 is determined for a particular package (FIG. 3), aspacer tool having a corresponding Z3 distance (FIGS. 4, 5) can beselected and used with the mount 710 to properly position the laser diewithin the package. In this way, z-axis alignment of the optoelectroniccomponent can be achieved regardless of the spacing needs encounteredwithin the package. This in turn enables the components of the packageto be manufactured with relatively less strict tolerances than wouldotherwise be required, thereby reducing overall manufacturing andassembly costs and providing production cost savings to themanufacturer.

Together with FIGS. 3-5, reference is now made to FIG. 6, which showsvarious details of one embodiment of a process by which optoelectroniccomponents can be properly aligned within a package. Note, however, thatFIG. 6 and the accompanying description depicts only certain details ofthe above process, and is not meant to include an exhaustive enumerationof a method for manufacturing an optical package. Further, principles ofthe present invention can be practiced using methods and components thatvary from that to be described below. The following discussion shouldnot, therefore, be construed as limiting of the present invention.

In detail, FIG. 6 shows a plurality of packages, such as the package 200shown in FIG. 3, in a manufacturing and assembly process conducted inpart by an alignment system 400. As depicted, in one embodiment thelaser package 200 can be imaged by an optical measurement device of thesystem 400, such as a camera 402. The camera 402 is equipped to imageportions of the laser package 200 in order to ascertain the dimensionsZ1 and Z2 as detailed above, and as shown in FIG. 3. Once the properdimensions have been ascertained by the camera 402 or similar device andthe dimension Z3 has been determined as above, the laser package 200 canproceed to a spacer tool handler 404.

In one embodiment, the spacer tool handler can contain multiple,differently-sized spacer tools having a range of unique Z3 dimensionsthat correspond to the range of possible desired Z3 dimensions that canbe encountered in the package 200, according to the tolerances of thepackage manufacturing process. Thus, the system 400 can adequately alignthe laser die 212 within the laser package 200 by first ascertaining theneed for proper spacing via the determination of the various dimensionsZ1 and Z2, then selecting the proper spacer tool from the spacer toolhandler 404.

Once the proper spacer tool is selected, an adhesive applicator 406 orother suitable component administers the adhesive 310 to the properportion of the laser package 200, such as the mounting surface 210 ofthe second package portion 206. A spacer tool applicator 408 or othersuitable component can be used to temporarily attach the laser die 212to the spacer tool 700 and insert the spacer tool within the packagesuch that the laser die is positioned at the proper package location inthe adhesive 310. Curing of the adhesive 310 can then occur to affix thelaser die 212 in the adhesive in a spaced-apart arrangement with respectto the mounting surface at the proper height within the laser package,as desired. The spacer tool 700 can then be removed and the laserpackage 200 can proceed as needed for further processing steps.

It is to be noted that the details of the system 400 are merelyexemplary, and thus should not be construed as the only manner in whichprinciples of the present invention can be practiced. It should also beremembered that, while the present discussion has focused on theplacement of a laser die within a laser package, embodiments of thepresent invention can be practiced with a variety of optoelectroniccomponents and packages, such as photodiodes placed within ROSApackages, for instance. Thus, this and other applications arecontemplated as falling within the claims of the present invention.

One advantage related to embodiments of the present invention is thefact that the practice of actively aligning the optoelectronic componentin the z-axis direction within the package can be reduced or eliminated,thereby representing further cost savings in the manufacture of thepackage.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrative,not restrictive. The scope of the invention is, therefore, indicated bythe appended claims rather than by the foregoing description. Allchanges that come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An optical subassembly, comprising: a package that defines a mountingsurface; an optical component positioned on the mounting surface at apredetermined distance from a reference point, wherein the opticalcomponent is positioned at the predetermined distance by a spacer tool,the spacer tool being interposed between the optical component and aspacer tool mount during optical component positioning, the spacer toolhaving a length that corresponds with a desired distance between theoptical component and the reference point.
 2. The optical subassembly asdefined in claim 1, wherein the optical component is attached to themounting surface at the predetermined distance via an adhesive.
 3. Theoptical subassembly as defined in claim 2, wherein the adhesive isselected from the group consisting of glue, solder, and adhesive strips.4. The optical subassembly as defined in claim 1, wherein the lens isincluded in the package, and wherein a distance extending from the lensto the reference point is used in determining the predeterminedposition.
 5. The optical subassembly as defined in claim 1, wherein themounting surface for the optical component is defined on a submount ofthe package.
 6. In an optoelectronic package, a method of positioning afirst component with respect to a second component, the methodcomprising: determining a desired position of the first component withrespect to the second component; determining an amount of spacingbetween the first component and a reference point that is required toposition the first component at the desired position; and employing aspacer tool that has a length equal to the required amount of spacing toposition the first component at the desired position; and affixing thefirst component at the desired position.
 7. The method of positioning asdefined in claim 6, wherein affixing the first component is achieved viaan adhesive applied to a mounting surface of the optoelectronic package.8. The method of positioning as defined in claim 6, wherein the firstcomponent is an optical component, and wherein the second component is alens.
 9. The method of positioning as defined in claim 6, whereindetermining the desired position and determining the amount of spacingare at least partially performed by a camera.
 10. A spacer tool systemfor use in aligning an optical component within an optoelectronicpackage, the spacer tool system comprising: a spacer tool having alength equal to a predetermined distance between the optical componentand a reference point of the optoelectronic package, the spacer toolbeing configured to temporarily hold the optical component at thepredetermined distance; a spacer tool mount attached to the spacer tooland configured such that the spacer tool temporarily holds the opticalcomponent at the predetermined distance, and such that the opticalcomponent can be affixed at the predetermined distance via an adhesive.11. The spacer tool system as defined in claim 10, wherein theoptoelectronic package includes a first package portion and a secondpackage portion, and wherein the reference point is defined at theinterface of the first and second package portions.
 12. The spacer toolsystem as defined in claim 11, wherein the first and second packageportions are separated during positioning of the optical component andwherein the spacer tool mount engages the second package portion at theinterface in order to enable the spacer tool to position the opticalcomponent at the predetermined distance.
 13. The spacer tool system asdefined in claim 12, wherein the optical component is aligned in adirection of propagation or reception of optical signals by the opticalcomponent.
 14. The spacer tool system as defined in claim 13, whereinthe predetermined distance is dependent on characteristics of theparticular package.
 15. The spacer tool as defined in claim 14, whereinthe spacer tool system includes a plurality of spacer tools that can beinterchanged according to the characteristics of the particular package.16. The spacer tool as defined in claim 15, wherein the optoelectronicpackage is positioned in one of a transmitter optical subassembly and areceiver optical subassembly.